Income Taxes - Reconciliation (Details) - USD ($)	12 Months Ended
	Dec. 25, 2016	Dec. 27, 2015	Dec. 28, 2014
Income Tax Expense
Tax at U.S. federal statutory rate	$ 55,583,000	$ 41,702,000	$ 39,989,000
State and local income taxes	2,972,000	2,106,000	1,896,000
Foreign income taxes	3,143,000	2,432,000	2,368,000
Income of consolidated partnerships attributable to noncontrolling interests	(2,312,000)	(2,311,000)	(1,608,000)
Non-qualified deferred compensation plan (income) loss	(428,000)	218,000	(171,000)
Tax credits	(6,771,000)	(4,846,000)	(3,906,000)
Other	(2,470,000)	(2,118,000)	(2,010,000)
Total	$ 49,717,000	$ 37,183,000	$ 36,558,000
Income Tax Rate
Tax at U.S. federal statutory rate (as a percent)	35.00%	35.00%	35.00%
State and local income taxes (as a percent)	1.90%	1.80%	1.70%
Foreign income taxes (as a percent)	2.00%	2.00%	2.10%
Income of consolidated partnerships attributable to noncontrolling interests (as a percent)	(1.40%)	(1.90%)	(1.40%)
Non-qualified deferred compensation plan (income) loss (as a percent)	(0.30%)	0.20%	(0.20%)
Tax credits	(4.30%)	(4.10%)	(3.40%)
Other (as a percent)	(1.60%)	(1.80%)	(1.80%)
Total	31.30%	31.20%	32.00%
Income taxes paid	$ 35,100,000	$ 23,300,000	$ 27,000,000
Decrease in liability for unrecognized tax benefits resulting from finalization of current examinations and other issues in the next 12 months	$ 267,000